AHA: Colchicine Prevents Postop Afib

by Ed Susman Contributing Writer, MedPage Today

Action Points

Explain that this study randomized patients in sinus rhythm undergoing cardiac surgery to colchicine or placebo, starting on postoperative day three.

The study showed a significant reduction in postoperative atrial fibrillation in the colchicine arm. Patients in the colchicine arm also had a shorter length of stay.

ORLANDO – The oral agent colchicine -- a drug almost as old as the hills -- appears to offer a new way to prevent atrial fibrillation (Afib) after heart surgery, researchers found.

The relative risk of developing postop Afib was reduced 42.1% if patients were treated with colchicine rather than placebo (P=0.002), said Massimo Imazio, MD, chief of cardiology at Maria Vittoria Hospital in Torino, Italy.

The incidence of atrial fibrillation at 12 months was 8.9% in patients given colchicine compared with 21.1% among patients randomized to placebo, he reported at the American Heart Association meeting.

"We would have to treat eight patients in order to prevent one case of postoperative atrial fibrillation," Imazio said during a press conference where he outlined the results of his trial, a substudy of the Colchicine for the Prevention of Postpericardiotomy Syndrome (COPPS) trial, which was also published simultaneously online in Circulation.

"Colchicine, administered prophylactically as an anti-inflammatory therapy, appears to halve the incidence of postoperative atrial fibrillation after cardiac surgery," commented Nancy Nussmeier, MD, the invited discussant of the paper.

Nussmeier, of the State University of New York Upstate Medical Center in Syracuse, N.Y., noted that colchicine "has been used for centuries for the treatment of gout, but it was only recently reviewed and approved by the FDA." She said the drug has also been shown to benefit patients in the secondary treatment of pericarditis.

Imazio and his team randomized 336 patients to receive either placebo (167) or colchicine (169) on the third day after surgery. Colchicine was dosed at 1 mg twice daily on the first day of therapy followed by a maintenance dose of 0.5 mg twice daily for a month in patients who weighed at least 70 kg. Patients who weighed less than 70 kg were treated with half doses twice a day.

An episode of atrial fibrillation was defined as arrhythmia that extended longer than five minutes.

In addition to achieving the primary endpoint of preventing postop Afib episodes, Imazio said the researchers also observed an 88.9% relative risk reduction in the secondary endpoint -- a composite of disease-related hospitalizations, cardiac tamponade, constrictive pericarditis, and recurrences. That endpoint was reached by 5% of the placebo patients compared with only 0.6% of the patients on colchicine (P=0.024).

The mean age of the patients in the study was about 65, and about 68% were men. The patients' medical histories were similar in both arms of the trial. About half the patients were undergoing coronary artery bypass graft surgery; about 25% were undergoing valvular surgery, and about 18% had combined cardiac procedures.

Imazio also reported that:

Pericardial effusion occurred in 12.8% of colchicine patients and in 22.8% of placebo patients (P=0.019).

Pleural effusions occurred in 12.2% of colchicine patients and in 25.6% of placebo patients (P=0.002).

All postoperative effusion was observed in 19.4% of colchicine patients and in 31.7% percent of placebo patients (P=0.017).

The research team is planning further studies, including treating patients on day one post-surgery. Imazio explained that starting treatment on day three followed the model of an earlier Israeli trial, which also started colchicine on day three. He said many cardiac surgery patients cannot be given oral medications right after surgery while in intensive care, but formulating the drug as a solution may get around that problem.

He also said plans were under way for a study that could begin colchicine therapy before surgery.

He said that further studies were needed before a recommendation to treat patients to prevent postoperative atrial fibrillation could be given.

Nussmeier agreed that further trials were necessary, but suggested that prophylactic treatment with colchicine was a "potentially cheap, effective, and relatively safe option for decreasing the incidence of postoperative atrial fibrillation."

MedPageToday is a trusted and reliable source for clinical and policy coverage that directly affects the lives and practices of health care professionals.

Physicians and other healthcare professionals may also receive Continuing Medical Education (CME) and Continuing Education (CE) credits at no cost for participating in MedPage Today-hosted educational activities.